This invention relates to the reactivation of the catalytic surfaces in a pollution prevention device especially for the exhaust from automotive vehicles. The generally known catalytic surfaces or particles used for the conversion of the exhaust gases to the nonpolluting gases, or for the removal of pollutants, become inactive in a relatively short time by the flow of exhaust fumes over the surfaces so that the anti-pollutant device becomes ineffective after a short period of use unless the catalytic material can be reactivated. This problem is particularly critical in automotive vehicles where adequate inspection to assure proper operation of the device is nonexistent.